// Copyright 2016 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef V8_ASMJS_ASM_TYPES_H_
#define V8_ASMJS_ASM_TYPES_H_

#include <string>

#include "src/base/compiler-specific.h"
#include "src/base/macros.h"
#include "src/globals.h"
#include "src/zone/zone-containers.h"
#include "src/zone/zone.h"

namespace v8 {
namespace internal {
    namespace wasm {

        class AsmType;
        class AsmFunctionType;
        class AsmOverloadedFunctionType;

// List of V(CamelName, string_name, number, parent_types)
#define FOR_EACH_ASM_VALUE_TYPE_LIST(V)                                         \
    /* These tags are not types that are expressable in the asm source. They */ \
    /* are used to express semantic information about the types they tag.    */ \
    V(Heap, "[]", 1, 0)                                                         \
    V(FloatishDoubleQ, "floatish|double?", 2, 0)                                \
    V(FloatQDoubleQ, "float?|double?", 3, 0)                                    \
    /* The following are actual types that appear in the asm source. */         \
    V(Void, "void", 4, 0)                                                       \
    V(Extern, "extern", 5, 0)                                                   \
    V(DoubleQ, "double?", 6, kAsmFloatishDoubleQ | kAsmFloatQDoubleQ)           \
    V(Double, "double", 7, kAsmDoubleQ | kAsmExtern)                            \
    V(Intish, "intish", 8, 0)                                                   \
    V(Int, "int", 9, kAsmIntish)                                                \
    V(Signed, "signed", 10, kAsmInt | kAsmExtern)                               \
    V(Unsigned, "unsigned", 11, kAsmInt)                                        \
    V(FixNum, "fixnum", 12, kAsmSigned | kAsmUnsigned)                          \
    V(Floatish, "floatish", 13, kAsmFloatishDoubleQ)                            \
    V(FloatQ, "float?", 14, kAsmFloatQDoubleQ | kAsmFloatish)                   \
    V(Float, "float", 15, kAsmFloatQ)                                           \
    /* Types used for expressing the Heap accesses. */                          \
    V(Uint8Array, "Uint8Array", 16, kAsmHeap)                                   \
    V(Int8Array, "Int8Array", 17, kAsmHeap)                                     \
    V(Uint16Array, "Uint16Array", 18, kAsmHeap)                                 \
    V(Int16Array, "Int16Array", 19, kAsmHeap)                                   \
    V(Uint32Array, "Uint32Array", 20, kAsmHeap)                                 \
    V(Int32Array, "Int32Array", 21, kAsmHeap)                                   \
    V(Float32Array, "Float32Array", 22, kAsmHeap)                               \
    V(Float64Array, "Float64Array", 23, kAsmHeap)                               \
    /* None is used to represent errors in the type checker. */                 \
    V(None, "<none>", 31, 0)

// List of V(CamelName)
#define FOR_EACH_ASM_CALLABLE_TYPE_LIST(V) \
    V(FunctionType)                        \
    V(OverloadedFunctionType)

        class AsmValueType {
        public:
            typedef uint32_t bitset_t;

            enum : uint32_t {
#define DEFINE_TAG(CamelName, string_name, number, parent_types) \
    kAsm##CamelName = ((1u << (number)) | (parent_types)),
                FOR_EACH_ASM_VALUE_TYPE_LIST(DEFINE_TAG)
#undef DEFINE_TAG
                    kAsmUnknown
                = 0,
                kAsmValueTypeTag = 1u
            };

        private:
            friend class AsmType;

            static AsmValueType* AsValueType(AsmType* type)
            {
                if ((reinterpret_cast<uintptr_t>(type) & kAsmValueTypeTag) == kAsmValueTypeTag) {
                    return reinterpret_cast<AsmValueType*>(type);
                }
                return nullptr;
            }

            bitset_t Bitset() const
            {
                DCHECK_EQ(reinterpret_cast<uintptr_t>(this) & kAsmValueTypeTag,
                    kAsmValueTypeTag);
                return static_cast<bitset_t>(reinterpret_cast<uintptr_t>(this) & ~kAsmValueTypeTag);
            }

            static AsmType* New(bitset_t bits)
            {
                DCHECK_EQ((bits & kAsmValueTypeTag), 0u);
                return reinterpret_cast<AsmType*>(
                    static_cast<uintptr_t>(bits | kAsmValueTypeTag));
            }

            // AsmValueTypes can't be created except through AsmValueType::New.
            DISALLOW_IMPLICIT_CONSTRUCTORS(AsmValueType);
        };

        class V8_EXPORT_PRIVATE AsmCallableType : public NON_EXPORTED_BASE(ZoneObject) {
        public:
            virtual std::string Name() = 0;

            virtual bool CanBeInvokedWith(AsmType* return_type,
                const ZoneVector<AsmType*>& args)
                = 0;

#define DECLARE_CAST(CamelName) \
    virtual Asm##CamelName* As##CamelName() { return nullptr; }
            FOR_EACH_ASM_CALLABLE_TYPE_LIST(DECLARE_CAST)
#undef DECLARE_CAST

        protected:
            AsmCallableType() = default;
            virtual ~AsmCallableType() = default;
            virtual bool IsA(AsmType* other);

        private:
            friend class AsmType;

            DISALLOW_COPY_AND_ASSIGN(AsmCallableType);
        };

        class V8_EXPORT_PRIVATE AsmFunctionType final : public AsmCallableType {
        public:
            AsmFunctionType* AsFunctionType() final { return this; }

            void AddArgument(AsmType* type) { args_.push_back(type); }
            const ZoneVector<AsmType*> Arguments() const { return args_; }
            AsmType* ReturnType() const { return return_type_; }

            bool CanBeInvokedWith(AsmType* return_type,
                const ZoneVector<AsmType*>& args) override;

        protected:
            AsmFunctionType(Zone* zone, AsmType* return_type)
                : return_type_(return_type)
                , args_(zone)
            {
            }

        private:
            friend AsmType;

            std::string Name() override;
            bool IsA(AsmType* other) override;

            AsmType* return_type_;
            ZoneVector<AsmType*> args_;

            DISALLOW_COPY_AND_ASSIGN(AsmFunctionType);
        };

        class V8_EXPORT_PRIVATE AsmOverloadedFunctionType final
            : public AsmCallableType {
        public:
            AsmOverloadedFunctionType* AsOverloadedFunctionType() override
            {
                return this;
            }

            void AddOverload(AsmType* overload);

        private:
            friend AsmType;

            explicit AsmOverloadedFunctionType(Zone* zone)
                : overloads_(zone)
            {
            }

            std::string Name() override;
            bool CanBeInvokedWith(AsmType* return_type,
                const ZoneVector<AsmType*>& args) override;

            ZoneVector<AsmType*> overloads_;

            DISALLOW_IMPLICIT_CONSTRUCTORS(AsmOverloadedFunctionType);
        };

        class V8_EXPORT_PRIVATE AsmType {
        public:
#define DEFINE_CONSTRUCTOR(CamelName, string_name, number, parent_types) \
    static AsmType* CamelName()                                          \
    {                                                                    \
        return AsmValueType::New(AsmValueType::kAsm##CamelName);         \
    }
            FOR_EACH_ASM_VALUE_TYPE_LIST(DEFINE_CONSTRUCTOR)
#undef DEFINE_CONSTRUCTOR

#define DEFINE_CAST(CamelCase)                                            \
    Asm##CamelCase* As##CamelCase()                                       \
    {                                                                     \
        if (AsValueType() != nullptr) {                                   \
            return nullptr;                                               \
        }                                                                 \
        return reinterpret_cast<AsmCallableType*>(this)->As##CamelCase(); \
    }
            FOR_EACH_ASM_CALLABLE_TYPE_LIST(DEFINE_CAST)
#undef DEFINE_CAST
            AsmValueType* AsValueType()
            {
                return AsmValueType::AsValueType(this);
            }
            AsmCallableType* AsCallableType();

            // A function returning ret. Callers still need to invoke AddArgument with the
            // returned type to fully create this type.
            static AsmType* Function(Zone* zone, AsmType* ret)
            {
                AsmFunctionType* f = new (zone) AsmFunctionType(zone, ret);
                return reinterpret_cast<AsmType*>(f);
            }

            // Overloaded function types. Not creatable by asm source, but useful to
            // represent the overloaded stdlib functions.
            static AsmType* OverloadedFunction(Zone* zone)
            {
                auto* f = new (zone) AsmOverloadedFunctionType(zone);
                return reinterpret_cast<AsmType*>(f);
            }

            // The type for fround(src).
            static AsmType* FroundType(Zone* zone);

            // The (variadic) type for min and max.
            static AsmType* MinMaxType(Zone* zone, AsmType* dest, AsmType* src);

            std::string Name();
            // IsExactly returns true if x is the exact same type as y. For
            // non-value types (e.g., callables), this returns x == y.
            static bool IsExactly(AsmType* x, AsmType* y);
            // IsA is used to query whether this is an instance of that (i.e., if this is
            // a type derived from that.) For non-value types (e.g., callables), this
            // returns this == that.
            bool IsA(AsmType* that);

            // The following methods are meant to be used for inspecting the traits of
            // element types for the heap view types.
            enum : int32_t { kNotHeapType = -1 };

            // Returns the element size if this is a heap type. Otherwise returns
            // kNotHeapType.
            int32_t ElementSizeInBytes();
            // Returns the load type if this is a heap type. AsmType::None is returned if
            // this is not a heap type.
            AsmType* LoadType();
            // Returns the store type if this is a heap type. AsmType::None is returned if
            // this is not a heap type.
            AsmType* StoreType();
        };

    } // namespace wasm
} // namespace internal
} // namespace v8

#endif // V8_ASMJS_ASM_TYPES_H_
